Brae oilfield
| Company type | Oil and gas field |
|---|---|
| Industry | Petroleum |
| Founded | 1974 |
| Founder | Pan Ocean |
| Headquarters | United Kingdom (Scottish waters) |
Area served | North Sea |
Key people | TAQA Bratani (operator) |
| Products | Oil, natural gas, natural gas liquids |
The Brae field is an oil reservoir located in Scottish waters, its name derived from a Scots term meaning hillside. Discovered in 1974 by well 16/7-1, which was drilled using the semi-submersible rig Odin Drill on behalf of operator Pan Ocean, this field lies within UKCS block 16/7a and is currently operated by TAQA Bratani.
This field consists of three main accumulations containing roughly 70 million tonnes of oil liquids alongside 22 cubic kilometres of natural gas. Production activities are centered on primary platforms that exploit the reserves beneath, with continuous infill drilling aimed at recovering remaining undrained zones. The operational lifespan of these platforms is extended through several subsea tieback developments. Gas extracted from the field is transported to St Fergus in Scotland via the SAGE pipeline, while oil is delivered through the Forties pipeline system.
Field reservoirs
The hydrocarbon reservoirs within the Brae field exhibit the following characteristics:
| Field | Brae South | Brae Central | Brae North |
|---|---|---|---|
| Reservoir | Upper Jurassic sandstones | Upper Jurassic formations | |
| Depth | 12,000–13,500 ft | Approximately 12,000 ft | |
| Oil column thickness | 1,500 ft | ||
| API gravity | 37° | 33° | 47° (NGL) |
| Sulfur content | 0.64 % | 0.64 % | |
| Gas Oil Ratio (GOR) | 1,400 scf/bbl | 5,000 scf/bbl | |
| Carbon dioxide concentration | Up to 35% | 8 % | |
| Pressure and temperature conditions | 7,200 psi, 240 °F | 7,000 psi, 240 °F | |
| Bubble point pressure | 3,688 psi | ||
| Recoverable oil reserves | 267 million barrels; 40 million tonnes | 65 million barrels; 9 million tonnes | 204 million barrels; 21 million tonnes |
| Recoverable natural gas liquids (NGL) | 33 million barrels NGL | 6 million barrels | |
| Recoverable gas volumes | 155 billion cubic feet | 682 billion cubic feet; 22 billion cubic metres |
Topside facilities
The topside facilities for Brae Alpha (Brae South) were engineered by Matthew Hall Engineering after securing the contract in August 1979. The platform was equipped with 19 wells dedicated to oil production, 14 water injection wells, two gas injection wells, and provision for 11 additional slots. Its production capacity reached up to 100,000 barrels of oil per day, alongside 12,000 barrels per day of Natural Gas Liquids (NGL) and 4.25 million standard cubic metres of gas daily. Two parallel production trains incorporated three-stage separation processes, with the initial stage operating at a notably high pressure of 248 bar. Power generation relied on four Rolls-Royce SK-30 gas turbines rated at 25 MW each. Accommodation facilities supported up to 240 personnel distributed over 14 topside modules with a total weight of approximately 31,000 tonnes.
Brae Bravo (Brae North) topsides were also designed by Matthew Hall Engineering following a contract awarded in October 1983. Initially installed were 12 oil production wells, three gas injection wells, and space for 19 spare slots. The platform’s capacity allowed for processing 75,000 barrels of liquid hydrocarbons daily and handling 11.3 million standard cubic metres of gas per day. It featured a single production train with four-stage separation beginning at a first-stage pressure of 103 bar. Electrical power was supplied by three Rolls-Royce/GEC ERB-124C gas turbines each rated at 24 MW. Accommodation was provided for 240 personnel within 21 modules weighing a combined total of around 33,000 tonnes.
East Brae’s topsides were designed under an October 1988 contract with Matthew Hall Engineering as well. The initial configuration included 13 oil wells, four gas injection wells, and capacity for 13 spare slots. Production capability amounted to 120,000 barrels of liquid hydrocarbons and 17.6 million standard cubic metres of gas daily. This platform operated a single production train with three-stage separation beginning at a first-stage pressure of 102 bar. Electric power was supplied through subsea cables from Brae Alpha and Bravo platforms. Accommodation supported up to 160 personnel with topsides weighing roughly 18,500 tonnes.
| Platform installation | Fabrication contractor | Construction site | Installation date |
|---|---|---|---|
| Brae Alpha | McDermott Scotland | Ardersier yard | April 1982 |
| Brae Bravo | McDermott Scotland | Ardersier yard | June 1987 |
| Brae East | Trafalgar House Offshore Fabricators | Methil yard | May 1993 |
See also
External links
| Platform | Brae Alpha | Brae Bravo |
|---|---|---|
| Platform type | Steel jacket | Steel jacket |
| Primary functions | Drilling, production, accommodation | Drilling, production, accommodation |
| Coordinates | 58°41’33”N 01°16’54”E | 58°47’32”N 01°20’51”E |
| Water depth | 112 m | 99.5 m |
| Jacket mass | 18,600 tonnes | 22,000 tonnes |
| Number of legs | 8 | 8 |
| Pile count | 36 | 36 |